The present invention is directed to an ordinary computer, and, particularly, to a portable computer operable on an internal battery. More particularly, the present invention relates to a system and a method of providing concentrated management of the power supply of the portable computer.
Various types of portable computers operable on an internal battery have recently been developed. This type of computer needs to always recognize the power status of a driving power and the statuses of individual units of the computer in both cases where an AC adapter is used and where an internal battery is used. It is also necessary to eliminate various problems originated from power failure including the lower usable state of the internal battery (hereinafter called low battery status) when power is supplied from the battery.
The present applicant has proposed one example of such a portable computer which is disclosed in the prior application Ser. No. 541,978. In brief, according from the disclosed computer, the battery power supply is constituted of a single main battery detachable to the body of the portable computer and an exclusive power controller CPU (PC-CPU) is used to control the charging of the main battery with the power supplied from an AC adapter. According to the portable computer disclosed in the above application, however, the PC-CPU controls a single battery power supply. When a liquid crystal display with a back light (EL-LCD), a plasma display (PDP) or the like is driven on power from the AC adapter, it is always necessary to supply power to the battery via the AC adapter in light of the power dissipation of the display. In addition, a large-capacity battery needs to be installed in the body of the computer. This significantly increases the weight of the overall computer, deteriorating the portability and hindering continuous battery driving over a long period of time.